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Rickets

Rickets is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Rickets rather than just read about it. In short: Rickets (scientific nomenclature: rachitis; from Greek ῥαχίτης rhakhítēs, meaning "in or of the spine" which was chosen as a back-formation, see Etymology) is a condition that results in weak or soft bones in children and may have either dietary-deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping.

Rickets — main illustration
Rickets — illustration

Key takeaways

  • Rickets belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Rickets to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Rickets from memory before moving on to harder problems.

Reference excerpt

Rickets (scientific nomenclature: rachitis; from Greek ῥαχίτης rhakhítēs, meaning "in or of the spine" which was chosen as a back-formation, see Etymology) is a condition that results in weak or soft bones in children and may have either dietary-deficiency or genetic causes. Symptoms include bowed legs, stunted growth, bone pain, large forehead, and trouble sleeping. Complications may include bone deformities, bone pseudofractures and fractures, muscle spasms, or an abnormally curved spine. The analogous condition in adults is osteomalacia. One can characterise a child who appears to suffer from rickets as rachitic. The most common cause of rickets is a vitamin-D deficiency, although hereditary genetic forms also exist. The condition can result from eating a diet without enough vitamin D, dark skin, too little sun exposure, exclusive breastfeeding without vitamin D supplementation, celiac disease, and certain genetic conditions. Other factors may include not enough calcium or phosphorus. The underlying mechanism involves insufficient calcification of the growth plate. Diagnosis is generally based on blood tests finding a low calcium, low phosphorus, and a high alkaline phosphatase together with X-rays. Prevention for exclusively breastfed babies is vitamin D supplements. Otherwise, treatment depends on the underlying cause. If due to a lack of vitamin D, treatment is usually with vitamin D and calcium. This generally results in improvements within a few weeks. Bone deformities may also improve over time. Occasionally, surgery may be performed to correct bone deformities. Genetic forms of the disease typically require specialized treatment. Rickets occurs relatively commonly in the Middle East, Africa, and Asia. It is generally uncommon in the United States and Europe, except among certain minority groups, but rates have been increasing among some populations. It begins in childhood, typically between the ages of 3 and 18 months of age. Rates of disease are equal in males and females. Cases of what is believed to have been rickets have been described since the 1st century AD, and the condition was widespread in the Roman Empire. The disease occurred commonly into the 20th century. Early treatments included the use of cod liver oil.

Signs and symptoms Signs and symptoms of dietary deficiency rickets can include bone tenderness, and a susceptibility for bone fractures, particularly greenstick fractures. Early skeletal deformities can arise in infants such as soft, thinned skull bones – a condition known as craniotabes, which is the first sign of rickets; skull bossing may be present and a delayed closure of the fontanelles. Young children may have bowed legs and thickened ankles and wrists; older children may have knock knees. Spinal curvatures of kyphoscoliosis or lumbar lordosis may be present. The pelvic bones may be deformed. A condition known as rachitic rosary can result from the thickening caused by nodules forming on the costochondral joints. This appears as a visible bump in the middle of each rib in a line on each side of the body. This somewhat resembles a rosary, giving rise to its name. The deformity of a pigeon chest may result in the presence of Harrison's groove. Hypocalcemia, a low level of calcium in the blood, can result in tetany – uncontrolled muscle spasms. Dental problems can also arise. An X-ray or radiograph of an advanced patient with rickets tends to present in a classic way: the bowed legs (outward curve of long bones of the legs) and a deformed chest. Changes in the skull also occur, causing a distinctive "square-headed" appearance known as "caput quadratum". These deformities persist into adult life if not treated. Long-term consequences include permanent curvatures or disfiguration of the long bones, and a curved back.

Cause Maternal deficiencies may be the cause of overt bone disease from before birth and impairment of bone quality after birth. The primary cause of congenital rickets is vitamin D deficiency in the mother's blood. Vitamin D ensures that serum phosphate and calcium levels are sufficient to facilitate the mineralization of bone. Congenital rickets may also be caused by other maternal diseases, including severe osteomalacia, untreated celiac disease, malabsorption, pre-eclampsia, and premature birth. Rickets in children is similar to osteomalacia in adults, and differs from osteoporosis, where there is increased porosity of bone leading to brittleness.. Prenatal care includes checking vitamin levels and ensuring that any deficiencies are supplemented. Exclusively breast-fed infants may require rickets prevention by vitamin D supplementation or increased exposure to sunlight. In sunny countries such as Nigeria, South Africa, and Bangladesh, there is sufficient endogenous vitamin D due to exposure to the sun. However, the disease occurs among older toddlers and children in these countries, which in these circumstances is attributed to low dietary calcium intakes due to a mainly cereal-based diet. Those at higher risk for developing rickets include:

Breast-fed infants whose mothers are not exposed to sunlight Breast-fed infants who are not exposed to sunlight Breast-fed babies who are exposed to little sunlight Adolescents, in particular when undergoing the pubertal growth spurt Any child whose diet does not contain enough vitamin D or calcium Diseases causing soft bones in infants, like hypophosphatasia or hypophosphatemia, can also lead to rickets. Strontium is allied with calcium uptake into bones; at excessive dietary levels, strontium has a rachitogenic (rickets-producing) action.

… excerpt ends here. Continue reading the full article.

Illustrations

Rickets illustration
Rickets: Widening of wrist
Widening of wrist
Rickets: Wrist X-ray showing changes in rickets. Mainly cupping is seen here.
Wrist X-ray showing changes in rickets. Mainly cupping is seen here.
Rickets: Chest X-ray showing changes consistent with rickets. These changes are usually referred to as "rosary beads" of rickets.
Chest X-ray showing changes consistent with rickets. These changes are usually referred to as "rosary beads" of rickets.
Rickets: Cholecalciferol (D3)
Cholecalciferol (D3)

Worked examples

Example 1 — a first encounter with Rickets

Start with the simplest possible case. Write down what Rickets claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Rickets before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Rickets ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Rickets

In research
Rickets appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Rickets in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Rickets is common in secondary-school and first-year university syllabi. It links to neighbouring topics Skeletal disorders, Vitamin D, Vitamin deficiencies, so understanding it makes those chapters shorter.
In everyday life
Look for Rickets outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Rickets in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Rickets means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Rickets out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Rickets in simple terms?

Rickets (scientific nomenclature: rachitis; from Greek ῥαχίτης rhakhítēs, meaning "in or of the spine" which was chosen as a back-formation, see Etymology) is a condition that results in weak or soft bones in children and may have either dietary-deficiency or genetic causes. Symptoms include bowed…

Why does Rickets matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Rickets?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Rickets.

Tags

  • Skeletal disorders
  • Vitamin D
  • Vitamin deficiencies

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